Siemens SIMATIC ET 200SP Communication Processors Missing Authentication For Critical Function (CVE-2025-40771)

critical Tenable OT Security Plugin ID 503756

Synopsis

The remote OT asset is affected by a vulnerability.

Description

Affected devices do not properly authenticate configuration connections. This could allow an unauthenticated remote attacker to access the configuration data.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

The following text was originally created by the Cybersecurity and Infrastructure Security Agency (CISA). The original can be found at CISA.gov.

Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk:

- All affected products: Restrict access to the affected systems to trusted IP addresses only
- All affected products: Update to V2.4.24 or later version

As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for industrial security and following recommendations in the product manuals.

Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage

For more information see the associated Siemens security advisory SSA-486936 in HTML and CSAF.

Plugin Details

Severity: Critical

ID: 503756

Version: 1.3

Type: remote

Family: Tenable.ot

Published: 10/27/2025

Updated: 10/28/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Vulnerability Information

CPE: cpe:/o:siemens:siplus_et_200sp_cp_1543sp-1_isec_tx_rail_firmware, cpe:/o:siemens:simatic_cp_1542sp-1_firmware:2.4.24, cpe:/o:siemens:simatic_cp_1542sp-1_irc_firmware:2.4.24, cpe:/o:siemens:siplus_et_200sp_cp_1543sp-1_isec_firmware:2.4.24, cpe:/o:siemens:siplus_et_200sp_cp_1542sp-1_irc_tx_rail_firmware:2.4.24, cpe:/o:siemens:simatic_cp_1543sp-1_firmware:2.4.24

Required KB Items: Tenable.ot/Siemens

Exploit Ease: No known exploits are available

Patch Publication Date: 10/14/2025

Vulnerability Publication Date: 10/14/2025

Reference Information

CVE: CVE-2025-40771

CWE: 306

Detections

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